Grid Impedance Estimation with Oversampling for Grid-Connected Converters

This paper presents a computationally simple estimation method of the grid impedance with the usage of a harmonic signal. To minimise the interference with the grid, an algorithm to define the start of the measurement is presented. Furthermore, oversampling of the current and voltage at the point of common coupling (PCC) is used to reduce the amplitude of the injected signal while still guaranteeing a high signal-to-noise ratio.