Admittance Model Identification of Inverters using Voltage Injection

The advancements in power electronics are leading to a growing number of electronic converters connected to the electric grid. Even though this enables a more efficient transformation and use of energy, the harmonic interaction between converters can cause instabilities in the network. Therefore, it is important to model the individual converters and their interconnection in an efficient way, in order to study the global stability of the system. A promising modelling strategy analytically derives the equivalent admittance of the converters. However, due to industrial secrecy issues, experimental identification methods are also necessary to obtain the converter equivalent admittance with a black-box approach. This paper analyses the experimental characterization of inverters using the voltage injection method. A detailed explanation of the theoretical background of this method and its practical implementation are provided.