Benchmark Study on Impedance Identification Methods for Grid Connected Converters

The increasing number of renewable energy sources connected to the grid also introduces large number of different power electronics converters into the system. This paper provides a comparative benchmark of methods to identify the frequency characteristics of a grid connected converter model. Analytical open-loop and closed-loop models are verified through offline simulations and real-time hardware-in-the-loop measurements. To verify the model and identify the transfer functions linking input and output variables, a pseudo-random binary sequence signal is used for perturbation in both cases.