Inverter Model Reconstruction from Terminal Measurements for Electromagnetic Transient Studies

Electromagnetic transient (EMT) inverter modeling for the study of converter/grid interactions is crucial for modern systems integrating distributed generation, electric vehicles, and microgrids. However, detailed inverter topologies are unavailable in many practical cases, precluding the implementation of analytical models. This paper presents a method for inverter model reconstruction from EMT terminal measurements. Previous use of the method - in conjunction with the numerical Laplace transform and two-port admittance modeling - successfully reconstructed wideband models of DC-DC converters and power transmission lines. An extension of the method to switched inverter modeling is described and evaluated here. A two-port model of an inverter is mathematically reconstructed using emulated EMT terminal measurements obtained from MATLAB/Simulink. The responses of reconstructed and simulated models to arbitrary voltage inputs under varying load conditions are compared to determine the accuracy of the estimated model. The results obtained indicate that the proposed method successfully reconstructs transient inverter models for both resistive and inductive loads.