Harmonic network impedance identification with pulse response analysis

The network impedance at a point of common coupling (PCC) of public mains is an essential parameter for design and control of power electronic systems connected to the PCC. Identifying its spectral characteristic is challenging, because it requires a measureable excitation of the network in the desired frequency range. Further on, the network impedance varies over time. Therefore, the identification process should be fast and repeatable. In this paper a system is presented, which allows a direct excitation of the network impedance on the medium-voltage level with defined current pulses. Short current pulse signals are evaluated and optimized in a simulation model in order to realize a precise and fast determination of the network impedance with this system.